1. Field of the Invention:
The present invention relates to a rearview mirror device for use on a motorcycle.
2. Description of the Relevant Art:
As shown in FIG. 7 of the accompanying drawings, many conventional motorcycles generally have rearview mirrors 103 disposed considerably upwardly of a handlebar 109. The motorcycle illustrated in FIG. 7 includes a cowling 102 which covers a front portion of the frame of the motorcycle. The rearview mirrors 103 are supported on respective stays 104 which project upwardly from opposite sides of the cowling 102.
With the rearview mirrors 103 positioned above the handlebar 109, since the rearview mirrors 103 give the rider a view of the area behind the motorcycle over the upper arms of the rider, it is necessary that the rearview mirrors 103 project laterally of the motorcycle beyond a certain distance. It is therefore difficult to increase the mechanical strength and rigidity of the stays 104 for the prevention of vibration of the rearview mirrors 103. If the diameter of the stays 104 were increased for greater rigidity, the weight of the upper portion of the motorcycle would be increased, and so would the area of forward projection of the motorcycle, resulting in increased air resistance or aerodynamic drag. Moreover, inasmuch as the stays 104 project laterally from the opposite sides of the cowling 102, the rigidity of an upper portion of the cowling 102 including a windshield 105 has to be increased.
Japanese Laid-Open Utility Model Publication No. 60-92686 discloses a rearview mirror device in which rearview mirrors are mounted on opposite sides of a cowling rearwardly of a handlebar. The disclosed rearview mirror device is however disadvantageous in that the angle of view when the rider gets a front view and the angle of view when the rider gets a rear view through the rearview mirrors are widely different from each other, i.e., the rider has to move his eyes through a large angle for a shift from a front view to a rear view or vice versa.
Another problem with the conventional rearview mirror device is that rain water deposited on an upper surface of the cowling while the motorcycle is running in rain tends to be attached to the reflecting surfaces of the rearview mirrors due to air turbulences developed at the upper ends of the rearview mirrors.